The precautions for blowing for H. pylori are as follows: First, the breath test for H. pylori is radioactive, and it is not recommended that children under eight years of age perfect this test, which may have some radiation and have an effect on certain neurological development. Second, before the test is recommended 6-8 hours fasting, can not take any drugs, and can not drink water. Third, the examination of H. pylori within a week can not take antibiotics, especially not cephalosporin antibiotics. Because amoxicillin or cephalosporin antibiotics have the effect of killing H. pylori, there will be a false negative result. Fourth, you need to drink more water and take more rest after the test to promote the excretion of radioactive elements. Check H. pylori, if the DPM is greater than 700, anti-H. pylori medication is needed.